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net: fec: Add software TSO support
Add software TSO support for FEC. This feature allows to improve outbound throughput performance. Tested on imx6dl sabresd board, running iperf tcp tests shows: - 16.2% improvement comparing with FEC SG patch - 82% improvement comparing with NO SG & TSO patch $ ethtool -K eth0 tso on $ iperf -c 10.192.242.167 -t 3 & [ 3] local 10.192.242.108 port 35388 connected with 10.192.242.167 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0- 3.0 sec 181 MBytes 506 Mbits/sec During the testing, CPU loading is 30%. Since imx6dl FEC Bandwidth is limited to SOC system bus bandwidth, the performance with SW TSO is a milestone. CC: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: David Laight <David.Laight@ACULAB.COM> CC: Li Frank <B20596@freescale.com> Signed-off-by: Fugang Duan <B38611@freescale.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Nimrod Andy
David S. Miller
parent
6e909283cb
commit
79f339125e
@ -299,6 +299,12 @@ struct fec_enet_private {
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unsigned short bufdesc_size;
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unsigned short tx_ring_size;
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unsigned short rx_ring_size;
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unsigned short tx_stop_threshold;
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unsigned short tx_wake_threshold;
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/* Software TSO */
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char *tso_hdrs;
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dma_addr_t tso_hdrs_dma;
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struct platform_device *pdev;
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@ -36,6 +36,7 @@
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#include <linux/in.h>
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#include <linux/ip.h>
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#include <net/ip.h>
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#include <net/tso.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/icmp.h>
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@ -228,6 +229,15 @@ MODULE_PARM_DESC(macaddr, "FEC Ethernet MAC address");
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#define FEC_PAUSE_FLAG_AUTONEG 0x1
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#define FEC_PAUSE_FLAG_ENABLE 0x2
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#define TSO_HEADER_SIZE 128
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/* Max number of allowed TCP segments for software TSO */
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#define FEC_MAX_TSO_SEGS 100
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#define FEC_MAX_SKB_DESCS (FEC_MAX_TSO_SEGS * 2 + MAX_SKB_FRAGS)
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#define IS_TSO_HEADER(txq, addr) \
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((addr >= txq->tso_hdrs_dma) && \
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(addr < txq->tso_hdrs_dma + txq->tx_ring_size * TSO_HEADER_SIZE))
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static int mii_cnt;
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static inline
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@ -438,8 +448,17 @@ static int fec_enet_txq_submit_skb(struct sk_buff *skb, struct net_device *ndev)
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unsigned short buflen;
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unsigned int estatus = 0;
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unsigned int index;
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int entries_free;
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int ret;
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entries_free = fec_enet_get_free_txdesc_num(fep);
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if (entries_free < MAX_SKB_FRAGS + 1) {
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dev_kfree_skb_any(skb);
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if (net_ratelimit())
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netdev_err(ndev, "NOT enough BD for SG!\n");
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return NETDEV_TX_OK;
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}
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/* Protocol checksum off-load for TCP and UDP. */
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if (fec_enet_clear_csum(skb, ndev)) {
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dev_kfree_skb_any(skb);
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@ -534,35 +553,210 @@ static int fec_enet_txq_submit_skb(struct sk_buff *skb, struct net_device *ndev)
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return 0;
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}
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static int
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fec_enet_txq_put_data_tso(struct sk_buff *skb, struct net_device *ndev,
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struct bufdesc *bdp, int index, char *data,
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int size, bool last_tcp, bool is_last)
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{
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struct fec_enet_private *fep = netdev_priv(ndev);
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const struct platform_device_id *id_entry =
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platform_get_device_id(fep->pdev);
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struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
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unsigned short status;
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unsigned int estatus = 0;
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status = bdp->cbd_sc;
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status &= ~BD_ENET_TX_STATS;
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status |= (BD_ENET_TX_TC | BD_ENET_TX_READY);
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bdp->cbd_datlen = size;
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if (((unsigned long) data) & FEC_ALIGNMENT ||
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id_entry->driver_data & FEC_QUIRK_SWAP_FRAME) {
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memcpy(fep->tx_bounce[index], data, size);
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data = fep->tx_bounce[index];
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if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME)
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swap_buffer(data, size);
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}
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bdp->cbd_bufaddr = dma_map_single(&fep->pdev->dev, data,
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size, DMA_TO_DEVICE);
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if (dma_mapping_error(&fep->pdev->dev, bdp->cbd_bufaddr)) {
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dev_kfree_skb_any(skb);
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if (net_ratelimit())
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netdev_err(ndev, "Tx DMA memory map failed\n");
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return NETDEV_TX_BUSY;
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}
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if (fep->bufdesc_ex) {
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if (skb->ip_summed == CHECKSUM_PARTIAL)
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estatus |= BD_ENET_TX_PINS | BD_ENET_TX_IINS;
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ebdp->cbd_bdu = 0;
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ebdp->cbd_esc = estatus;
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}
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/* Handle the last BD specially */
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if (last_tcp)
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status |= (BD_ENET_TX_LAST | BD_ENET_TX_TC);
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if (is_last) {
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status |= BD_ENET_TX_INTR;
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if (fep->bufdesc_ex)
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ebdp->cbd_esc |= BD_ENET_TX_INT;
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}
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bdp->cbd_sc = status;
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return 0;
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}
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static int
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fec_enet_txq_put_hdr_tso(struct sk_buff *skb, struct net_device *ndev,
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struct bufdesc *bdp, int index)
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{
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struct fec_enet_private *fep = netdev_priv(ndev);
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const struct platform_device_id *id_entry =
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platform_get_device_id(fep->pdev);
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int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
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struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
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void *bufaddr;
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unsigned long dmabuf;
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unsigned short status;
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unsigned int estatus = 0;
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status = bdp->cbd_sc;
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status &= ~BD_ENET_TX_STATS;
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status |= (BD_ENET_TX_TC | BD_ENET_TX_READY);
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bufaddr = fep->tso_hdrs + index * TSO_HEADER_SIZE;
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dmabuf = fep->tso_hdrs_dma + index * TSO_HEADER_SIZE;
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if (((unsigned long) bufaddr) & FEC_ALIGNMENT ||
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id_entry->driver_data & FEC_QUIRK_SWAP_FRAME) {
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memcpy(fep->tx_bounce[index], skb->data, hdr_len);
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bufaddr = fep->tx_bounce[index];
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if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME)
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swap_buffer(bufaddr, hdr_len);
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dmabuf = dma_map_single(&fep->pdev->dev, bufaddr,
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hdr_len, DMA_TO_DEVICE);
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if (dma_mapping_error(&fep->pdev->dev, dmabuf)) {
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dev_kfree_skb_any(skb);
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if (net_ratelimit())
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netdev_err(ndev, "Tx DMA memory map failed\n");
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return NETDEV_TX_BUSY;
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}
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}
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bdp->cbd_bufaddr = dmabuf;
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bdp->cbd_datlen = hdr_len;
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if (fep->bufdesc_ex) {
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if (skb->ip_summed == CHECKSUM_PARTIAL)
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estatus |= BD_ENET_TX_PINS | BD_ENET_TX_IINS;
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ebdp->cbd_bdu = 0;
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ebdp->cbd_esc = estatus;
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}
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bdp->cbd_sc = status;
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return 0;
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}
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static int fec_enet_txq_submit_tso(struct sk_buff *skb, struct net_device *ndev)
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{
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struct fec_enet_private *fep = netdev_priv(ndev);
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int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
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int total_len, data_left;
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struct bufdesc *bdp = fep->cur_tx;
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struct tso_t tso;
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unsigned int index = 0;
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int ret;
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if (tso_count_descs(skb) >= fec_enet_get_free_txdesc_num(fep)) {
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dev_kfree_skb_any(skb);
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if (net_ratelimit())
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netdev_err(ndev, "NOT enough BD for TSO!\n");
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return NETDEV_TX_OK;
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}
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/* Protocol checksum off-load for TCP and UDP. */
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if (fec_enet_clear_csum(skb, ndev)) {
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dev_kfree_skb_any(skb);
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return NETDEV_TX_OK;
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}
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/* Initialize the TSO handler, and prepare the first payload */
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tso_start(skb, &tso);
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total_len = skb->len - hdr_len;
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while (total_len > 0) {
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char *hdr;
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index = fec_enet_get_bd_index(fep->tx_bd_base, bdp, fep);
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data_left = min_t(int, skb_shinfo(skb)->gso_size, total_len);
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total_len -= data_left;
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/* prepare packet headers: MAC + IP + TCP */
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hdr = fep->tso_hdrs + index * TSO_HEADER_SIZE;
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tso_build_hdr(skb, hdr, &tso, data_left, total_len == 0);
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ret = fec_enet_txq_put_hdr_tso(skb, ndev, bdp, index);
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if (ret)
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goto err_release;
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while (data_left > 0) {
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int size;
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size = min_t(int, tso.size, data_left);
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bdp = fec_enet_get_nextdesc(bdp, fep);
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index = fec_enet_get_bd_index(fep->tx_bd_base, bdp, fep);
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ret = fec_enet_txq_put_data_tso(skb, ndev, bdp, index, tso.data,
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size, size == data_left,
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total_len == 0);
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if (ret)
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goto err_release;
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data_left -= size;
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tso_build_data(skb, &tso, size);
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}
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bdp = fec_enet_get_nextdesc(bdp, fep);
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}
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/* Save skb pointer */
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fep->tx_skbuff[index] = skb;
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fec_enet_submit_work(bdp, fep);
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skb_tx_timestamp(skb);
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fep->cur_tx = bdp;
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/* Trigger transmission start */
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writel(0, fep->hwp + FEC_X_DES_ACTIVE);
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return 0;
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err_release:
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/* TODO: Release all used data descriptors for TSO */
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return ret;
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}
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static netdev_tx_t
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fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
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{
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struct fec_enet_private *fep = netdev_priv(ndev);
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struct bufdesc *bdp;
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unsigned short status;
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int entries_free;
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int ret;
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/* Fill in a Tx ring entry */
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bdp = fep->cur_tx;
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status = bdp->cbd_sc;
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if (status & BD_ENET_TX_READY) {
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/* Ooops. All transmit buffers are full. Bail out.
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* This should not happen, since ndev->tbusy should be set.
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*/
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if (net_ratelimit())
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netdev_err(ndev, "tx queue full!\n");
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return NETDEV_TX_BUSY;
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}
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ret = fec_enet_txq_submit_skb(skb, ndev);
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if (skb_is_gso(skb))
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ret = fec_enet_txq_submit_tso(skb, ndev);
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else
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ret = fec_enet_txq_submit_skb(skb, ndev);
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if (ret)
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return ret;
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entries_free = fec_enet_get_free_txdesc_num(fep);
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if (entries_free < MAX_SKB_FRAGS + 1)
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if (entries_free <= fep->tx_stop_threshold)
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netif_stop_queue(ndev);
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return NETDEV_TX_OK;
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@ -883,7 +1077,7 @@ fec_enet_tx(struct net_device *ndev)
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unsigned short status;
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struct sk_buff *skb;
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int index = 0;
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int entries;
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int entries_free;
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fep = netdev_priv(ndev);
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bdp = fep->dirty_tx;
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@ -900,8 +1094,9 @@ fec_enet_tx(struct net_device *ndev)
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index = fec_enet_get_bd_index(fep->tx_bd_base, bdp, fep);
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skb = fep->tx_skbuff[index];
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dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr, bdp->cbd_datlen,
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DMA_TO_DEVICE);
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if (!IS_TSO_HEADER(fep, bdp->cbd_bufaddr))
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dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
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bdp->cbd_datlen, DMA_TO_DEVICE);
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bdp->cbd_bufaddr = 0;
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if (!skb) {
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bdp = fec_enet_get_nextdesc(bdp, fep);
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@ -962,9 +1157,11 @@ fec_enet_tx(struct net_device *ndev)
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/* Since we have freed up a buffer, the ring is no longer full
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*/
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entries = fec_enet_get_free_txdesc_num(fep);
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if (entries >= MAX_SKB_FRAGS + 1 && netif_queue_stopped(ndev))
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netif_wake_queue(ndev);
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if (netif_queue_stopped(ndev)) {
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entries_free = fec_enet_get_free_txdesc_num(fep);
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if (entries_free >= fep->tx_wake_threshold)
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netif_wake_queue(ndev);
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}
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}
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return;
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}
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@ -2166,6 +2363,9 @@ static int fec_enet_init(struct net_device *ndev)
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fep->tx_ring_size = TX_RING_SIZE;
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fep->rx_ring_size = RX_RING_SIZE;
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fep->tx_stop_threshold = FEC_MAX_SKB_DESCS;
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fep->tx_wake_threshold = (fep->tx_ring_size - fep->tx_stop_threshold) / 2;
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if (fep->bufdesc_ex)
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fep->bufdesc_size = sizeof(struct bufdesc_ex);
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else
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@ -2179,6 +2379,13 @@ static int fec_enet_init(struct net_device *ndev)
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if (!cbd_base)
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return -ENOMEM;
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fep->tso_hdrs = dma_alloc_coherent(NULL, fep->tx_ring_size * TSO_HEADER_SIZE,
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&fep->tso_hdrs_dma, GFP_KERNEL);
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if (!fep->tso_hdrs) {
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dma_free_coherent(NULL, bd_size, cbd_base, fep->bd_dma);
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return -ENOMEM;
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}
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memset(cbd_base, 0, PAGE_SIZE);
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fep->netdev = ndev;
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@ -2209,9 +2416,11 @@ static int fec_enet_init(struct net_device *ndev)
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ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
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if (id_entry->driver_data & FEC_QUIRK_HAS_CSUM) {
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ndev->gso_max_segs = FEC_MAX_TSO_SEGS;
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/* enable hw accelerator */
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ndev->features |= (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM
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| NETIF_F_RXCSUM | NETIF_F_SG);
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| NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_TSO);
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fep->csum_flags |= FLAG_RX_CSUM_ENABLED;
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}
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